Card device

ABSTRACT

According to one embodiment, a card device includes an authentication unit, a wireless communication unit, and a control unit. The authentication unit performs an authentication process with an external device via wired communication. The wireless communication unit performs wireless communication with the external device. The control unit controls the wireless communication unit to reduce radio waves radiated from the wireless communication unit when the control unit detects that the authentication process is being performed.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2011-155893, filed on Jul. 14, 2011; theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a card device.

BACKGROUND

There has been conventionally known a card device that includes mountedtherein an authentication unit configured to perform an authenticationprocess with an external device via wired communication and a wirelesscommunication unit configured to perform wireless communication totransmit and receive data.

For performing wireless communication, various electronic circuits aredriven, and electromagnetic noise (radio waves) is radiated from suchelectronic circuits. Accordingly, if wireless communication is performedwhile an authentication process is being performed, an error may occurin the authentication result under the influence of electromagneticnoise caused with the wireless communication. In particular, since theauthentication unit and the wireless communication unit are placed closeto each other in a small space of the card device, electromagnetic noiseradiated from the wireless communication unit has a significant impacton the authentication process performed by the authentication unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an exemplary schematic configuration ofa communication system according to a first embodiment;

FIG. 2 is a diagram illustrating an example of procedures for stoppingthe operation of a wireless communication unit;

FIG. 3 is a diagram illustrating another example of procedures forstopping the operation of the wireless communication unit;

FIG. 4 is a diagram illustrating an exemplary schematic configuration ofa communication system according to a second embodiment;

FIG. 5 is a diagram illustrating a modified example of a card deviceaccording to the second embodiment; and

FIG. 6 is a diagram illustrating an exemplary configuration of a carddevice according to a third embodiment.

DETAILED DESCRIPTION

According to one embodiment, a card device includes an authenticationunit, a wireless communication unit, and a control unit. Theauthentication unit performs an authentication process with an external,device via wired communication. The wireless communication unit performswireless communication with the external device. The control unitcontrols the wireless communication unit to reduce radio waves radiatedfrom the wireless communication unit when the control unit detects thatthe authentication process is being performed.

Various embodiments will be described below in detail with reference tothe accompanying drawings.

First Embodiment

FIG. 1 is a block diagram illustrating an exemplary schematicconfiguration of a communication system 100 according to a firstembodiment. As illustrated in FIG. 1, the communication system 100includes a portable device (equipment) 20 in which a card device 10 ismounted and an external device 30. The device 20 may be of any type, andexamples thereof include a cellular phone handset and a card-typeterminal such as Suica (registered trademark). The external device 30 isa device that can communicate with the device 20, and may be a serverdevice or a reader/writer capable of reading and writing data from/tothe card device 10 mounted in the device 20, for example. Although acase where only one external device 30 capable of communicating with thedevice 20 is used is illustrated in FIG. 1, any number of the externaldevices 30 capable of communicating with the device 20 may be used, andthere may be two or more external devices 30, for example.

The card device 10 is an electronic device in which various electroniccomponents are mounted. As illustrated in FIG. 1, the card device 10includes an authentication unit 40, a wireless communication unit 50 anda control unit 60. The authentication unit 40 performs an authenticationprocess with the external device 30 via wired communication. Theauthentication unit 40 may be a secure element, for example. Asillustrated in FIG. 1, the authentication unit 40 is connected to adevice's wireless communication unit 21 provided in the device 20 via asignal line 101 used for wired communication. The device's wirelesscommunication unit 21 wirelessly communicates with the external device30. Although not illustrated in detail, the device's wirelesscommunication unit 21 includes an electronic circuit, an antenna and thelike for performing wireless communication. Examples of the antennaincluded in the device's wireless communication unit 21 include anantenna for near field communication (NFC) and an antenna for 3G. Theantenna, however, is not limited thereto and any type of antenna can beemployed. When the antenna for NEC is employed, this part may be calleda contactless front end (CLF). In addition, the “authentication process”described above refers to a process for authenticating the card device10. In this embodiment, the authentication of the card device 10 isperformed by determining whether or not an identification numberassigned to the card device 10 matches a preregistered identificationnumber.

More specifically, the external device 30 first transmits a requestsignal requesting transmission of the identification number to thedevice 20. The request signal received by the device's wirelesscommunication unit 21 is transmitted to the authentication unit 40 viathe signal line 101. The authentication unit 40 that has received therequest signal transmits the identification number assigned to the carddevice 10 to the external device 30 via the signal line 101 and thedevice's wireless communication unit 21. The authentication unit 40 mayencrypt the identification number before transmission, for example. Theexternal device 30 then decrypts the identification number transmittedfrom the device 20 in response to the request signal and determineswhether or not the identification number obtained by the decrypt matchesthe preregistered identification number to authenticate the card device10 mounted in the device 20. Note that a process for receiving therequest signal by the authentication unit 40, a process for transmittingthe identification number by the authentication unit 40 and the likecorrespond to the authentication process performed by the authenticationunit 40, but these are only one example of the authentication process.Various known methods can be employed for the authentication process.

The wireless communication unit 50 performs wireless communication viaradio waves with the external device 30. Although not illustrated indetail, the wireless communication unit 50 includes an electroniccircuit, an antenna and the like for performing wireless communication.

When the control unit 60 detects that the authentication process isbeing performed by the authentication unit 40, the control unit 60performs control to reduce the electromagnetic noise (radio waves)radiated from the wireless communication unit 50. Detailed descriptionthereof will be given as follows. In this embodiment, the control unit60 detects whether the authentication process is being performed on thebasis of the state of the signal line 101. Since the authentication unit40 performs the authentication process with the external device 30 viawired communication, a predetermined signal (a signal used for theauthentication process) is transmitted through the signal line 101 whenthe authentication process is performed. More specifically, the currentflowing through the signal line 101 and the voltage level thereonchange. Since the current flowing through the signal line 101 and thevoltage level thereon do not change when wired communication is notperformed (that is, when the authentication process is not performed),it is possible to detect that the authentication process is beingperformed by detecting changes in the current flowing through the signalline 101 and the voltage level thereon.

When the control unit 60 detects that the authentication process isbeing performed as described above, the control unit 60 performs controlto reduce the electromagnetic noise radiated from the wirelesscommunication unit 50. For example, in this embodiment, when the controlunit 60 detects that the authentication process is being performed, thecontrol unit 60 controls the wireless communication unit 50 such thatthe operation of the wireless communication unit 50 is stopped. As aresult of stopping the operation of the wireless communication unit 50,the electromagnetic noise radiated from the wireless communication unit50 can be mostly eliminated.

Alternatively, the control unit 60 may reduce the data transfer rate ofthe wireless communication unit 50, for example. In general, the powerconsumption at an electronic circuit tends to be larger as the datatransfer rate is higher, and the electromagnetic noise is also increasedwith the increase in the data transfer rate. The electromagnetic noisecan therefore be reduced by lowering the data transfer rate.

Alternatively, the control unit 60 may make the wireless communicationunit 50 operate intermittently. As a result of making the wirelesscommunication unit 50 operate intermittently, there is a period duringwhich the wireless communication unit 50 is stopped. Thus, the averageamount of electromagnetic noise during a given period can be reduced. Ifthe wireless communication unit 50 also operates intermittently duringnormal operation, the periods of the intermittent operation may be madelonger. As a result, the average amount of electromagnetic noise duringa given period can be reduced.

Alternatively, the control unit 60 may stop power supply to the wirelesscommunication unit 50, for example. As a result, the electromagneticnoise radiated from the wireless communication unit 50 can be completelyeliminated.

Next, procedures for stopping the operation of the wirelesscommunication unit 50 will be described. For example, as illustrated inFIG. 2, when the control unit 60 detects that the authentication processis being performed, the control unit 60 may control the wirelesscommunication unit 50 such that the operation of the wirelesscommunication unit 50 is stopped and may also control the wirelesscommunication unit 50 to transmit a stop request requesting to stopoperating to an external wireless communication unit of the externaldevice 30. Alternatively, with a configuration in which the externaldevice 30 includes an external authentication unit configured to performan authentication process and an external control unit configured tostop the operation of the external wireless communication unit when itis detected that an authentication process is being performed, forexample, when the control unit 60 detects that the authenticationprocess is being performed, the control unit 60 may control the wirelesscommunication unit 50 such that the operation of the wirelesscommunication unit 50 is stopped and the external control unit maycontrol the external wireless control unit such that the operation ofthe external wireless communication unit is stopped as illustrated inFIG. 3.

For example, the control unit 60 may resume the operation of thewireless communication unit 50 after elapse of a predetermined timeperiod from when the operation of the wireless communication unit 50 isstopped. Alternatively, the control unit 60 may resume the operation ofthe wireless communication unit 50 when the period during which theauthentication process being performed is not detected has lasted longerthan a predetermined length, for example.

While the procedures described above are those for stopping theoperation of the wireless communication unit 50, procedures for loweringthe data transfer rate of the wireless communication unit 50, for makingthe wireless communication unit 50 operate intermittently or the likeare similar to those described above.

As described above, in this embodiment, when the control unit 60 detectsthat the authentication process is being performed, the control unit 60performs control to reduce the electromagnetic noise radiated from thewireless communication unit 50. Therefore, an advantageous effect thatoccurrence of errors in the authentication result under the influence ofthe electromagnetic noise radiated from the wireless communication unit50 can be reduced is produced.

Second Embodiment

Next, a second embodiment will be described. The second embodiment isdifferent from the first embodiment in that the control unit 60 detectswhether the authentication process is being performed on the basis ofthe state of power supply to the authentication unit 40. Detaileddescription thereof will be given below. Note that description of partsthat are the same as those in the first embodiment will not be repeatedas appropriate.

FIG. 4 is a block diagram illustrating an exemplary schematicconfiguration of a communication system 100 according to the secondembodiment. In this example, power is supplied to the device 20 throughelectromagnetic induction using lines of magnetic force generated by theexternal device 30 when the device 20 is brought close to the externaldevice 30. More specifically, the device's wireless communication unit21 includes a coil, and current is generated in the coil of the device'swireless communication unit 21 when the lines of magnetic force emittedfrom the external device 30 pass through the coil. The generated currentis rectified and smoothened by a power supply unit 22 provided in thedevice 20, and supplied to the authentication unit 40 via a power line102. After power is supplied to the authentication unit 40 and theauthentication unit 40 is activated, the authentication process isstarted.

In this embodiment, the control unit 60 detects whether theauthentication process is being performed on the basis of the state ofthe power line 102. More specifically, the control unit 60 can detectwhether or not power is being supplied to the power line 102 on thebasis of the current flowing through the power line 102 and the voltagelevel thereon. When the control unit 60 detects that power is beingsupplied to the power line 102, the control unit 60 detects that theauthentication process is being performed and performs control to reducethe electromagnetic noise radiated from the wireless communication unit50 similarly to the first embodiment.

As described above, since the authentication unit 40 starts theauthentication process after receiving power supply and being activated,the authentication process is not yet performed at the time point whenthe power supply to the power line 102 is started. Accordingly, thecontrol unit 60 preferably performs control to reduce theelectromagnetic noise radiated from the wireless communication unit 50when the control unit 60 detects that the power supply to the power line102 is started. As a result, noise radiated from the wirelesscommunication unit 50 can be reduced before the authentication processis started. There is thus an advantage that occurrence of errors in theauthentication result can be reduced as compared to a configuration bywhich noise radiated from the wireless communication unit 50 is reducedduring the authentication process.

In this embodiment, the authentication unit 40 performs theauthentication process after receiving power supply. The method ofdetecting whether the authentication process is being performed on thebasis of the state of the power line 102 is therefore more advantageousin that the authentication process being performed can be detected at anearlier timing than the method of detecting whether the authenticationprocess is being performed on the basis of the state of the signal line101.

Alternatively, a configuration in which a power source unit 70 thatincludes a battery or the like is provided in the card device 10 asillustrated in FIG. 5 may be used instead of power supply to the device20 through electromagnetic induction as described above. Power from thepower source unit 70 is supplied to the authentication unit 40 via apower line 71. The control unit 60 may control the power source unit 70to supply power to the authentication unit 40 when the control unit 60detects that a signal used for an authentication process is output tothe signal line 101. With such a configuration as well, the control unit60 can detect that the authentication process is being performed bydetecting power supply to the power line 71.

With the configuration described above, occurrence of errors in theauthentication result under the influence of the electromagnetic noiseradiated from the wireless communication unit 50 can be reduced.

Third Embodiment

Next, a third embodiment will be described. The third embodiment isdifferent from the first embodiment in that the authentication unit 40outputs a signal (hereinafter referred to as an “indicator signal”)indicating that the authentication process is being performed to thecontrol unit 60 when performing the authentication process, and that thecontrol unit 60 detects that the authentication process is beingperformed when the indicator signal is received. Detailed descriptionthereof will be given below. Note that description of parts that are thesame as those in the first embodiment will not be repeated asappropriate.

FIG. 6 is a diagram illustrating an exemplary configuration of a carddevice 10 according to the third embodiment. As illustrated in FIG. 6,the difference from the first embodiment is that the card device 10further includes an indicator line 103 connecting the authenticationunit 40 and the control unit 60. In this embodiment, the authenticationunit 40 outputs an indicator signal when performing the authenticationprocess. The indicator signal is transmitted to the control unit 60 viathe indicator line 103. The control unit 60 detects that theauthentication process is being performed when the control unit 60receives the indicator signal, and performs control to reduce theelectromagnetic noise radiated from the wireless communication unit 50similarly to the first embodiment. With this configuration as well,occurrence of errors in the authentication result under the influence ofthe electromagnetic noise radiated from the wireless communication unit50 can be reduced.

Any type of the card device 10 may be used, and examples thereof includean SD card, a micro SD card, a SIM card and an IC card.

Moreover, when the control unit 60 detects that the authenticationprocess is being performed, it may control the wireless communicationunit 50 to perform only a connection process for connecting with adevice to communicate with after the authentication process but not toperform transmission/reception of data. The device to communicate withafter the authentication process may be the external device 30 for whichthe authentication process is performed or may be another externaldevice 30. Note that, when data are to be transmitted/received throughwireless communication, the connection process needs to be performedbefore the transmission/reception. The connection process, however,typically requires a smaller amount of processing thantransmission/reception of data, and the amount of electromagnetic noiseradiated from the wireless communication unit 50 thus tends to besmaller. In addition, when data are to be transmitted/received to/from acertain external device 30 after completion of the authenticationprocess, performing the connection process for connecting with thisexternal device 30 during the authentication process allows thetransmission/reception of data after the authentication process to bestarted promptly. According to the above-described configuration,advantageous effects that occurrence of errors in the authenticationresult under the influence of the electromagnetic noise radiated fromthe wireless communication unit 50 can be reduced and thattransmission/reception of data after the authentication process can bestarted promptly are therefore produced. Note that the connectionprocess for connecting with the external device 30 means a process forgetting ready for communication with the external device 30.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A card device comprising: an authenticator thatperforms an authentication process for authenticating the card devicewith an external device via wired communication, wherein theauthenticator is connected to a signal line used for the wiredcommunication; a wireless communicator that performs wirelesscommunication for at least one process that is different from theauthentication process, wherein the wireless communicator is notconnected to the signal line; and a controller that performs control toreduce radio waves radiated from the wireless communicator when thecontroller detects that the authentication process is being performed.2. The card device according to claim 1, wherein when the controllerdetects that the authentication process is being performed, thecontroller controls the wireless communicator to perform only aconnection process for connecting to a device to communicate after theauthentication process but not to perform transmission and reception ofdata.
 3. The card device according to claim 1, wherein the controllerdetects whether the authentication process is being performed based on astate of the signal line used for the wired communication.
 4. The carddevice according to claim 1, further comprising a power line connectedto the authenticator and used for supplying power to the authenticator,wherein the controller detects whether the authentication process isbeing performed based on a state of the power line.
 5. The card deviceaccording to claim 1, wherein when performing the authenticationprocess, the authenticator outputs, to the controller, a signalindicating that the authentication process is being performed, and thecontroller detects that the authentication process is being performedwhen the controller receives the signal.
 6. The card device according toclaim 1, wherein the wireless communicator includes an antenna.
 7. Acellular phone handset comprising: the card device according to claim 1.8. A method for performing control by a card device, the methodcomprising: performing an authentication process for authenticating thecard device with an external device via wired communication using aconnection to a signal line; performing wireless communication for atleast one process that is different from the authentication process,wherein the wireless communication is performed not using a connectionto the signal line; and performing control to reduce radio wavesradiated due to the wireless communication when execution of theauthentication process is detected.
 9. A card device comprising: anauthenticator that performs an authentication process for authenticatingthe card device with an external device via wired communication, whereinthe authenticator is connected to a signal line used for the wiredcommunication; a wireless communicator that performs wirelesscommunication, wherein the wireless communicator is not connected to thesignal line; a power line connected to the authenticator and used forsupplying power to the authenticator; and a controller that performscontrol to reduce radio waves radiated from the wireless communicatorwhen the controller detects that supply of power to the power line isstarted, before the authentication process is started.
 10. The carddevice according to claim 9, wherein when the controller detects thatthe authentication process is being performed, the controller controlsthe wireless communicator to perform only a connection process forconnecting to a device to communicate with after the authenticationprocess but not to perform transmission and reception of data.
 11. Thecard device according to claim 9, wherein the controller detects whetherthe authentication process is being performed based on a state of thesignal line used for the wired communication.
 12. The card deviceaccording to claim 9, wherein when performing the authenticationprocess, the authenticator outputs, to the controller, a signalindicating that the authentication process is being performed, and thecontroller detects that the authentication process is being performedwhen the controller receives the signal.
 13. The card device accordingto claim 9, wherein the wireless communicator includes an antenna.
 14. Acellular phone handset comprising: the card device according to claim 9.